Mammography is a specific type of imaging that uses a low-dose x-ray system and high-contrast, high-resolution film for examination of the breasts. Most medical experts agree that successful treatment of breast cancer often is linked to early diagnosis. Mammography plays a central part in early detection of breast cancers because it can show changes in the breast up to two years before a patient or physician can feel them. Current guidelines from the U.S. Department of Health and Human Services (HHS), the American Cancer Society (ACS), the American Medical Association (AMA) and the American College of Radiology (ACR) recommend screening mammography every one to two years for women, beginning at age 40.
X-ray photography of the female breast constitutes one branch of the broader field relating to diagnostic X-ray photography of soft tissues, but the preparation of X-ray pictures of the female breast is very difficult, particularly in that the correct adjustment and focusing of the system is rather complicated. In the prior art, it was the general practice to prepare mammograms by utilizing the available standard X-ray installations, while equipping such installations with auxiliary devices. While it was possible to obtain satisfactory results in this way, there were various drawbacks and disadvantages. For example, the female patient rarely remained in the desired standard position during the preparation of the mammogram. Moreover, the problems of focusing and adjustment were so difficult that the quality of the results was variable and rather unpredictable.
Thus, the desire arose to provide a special X-ray machine which would satisfy the demands of the physicians for easy and accurate focusing and adjustment of the machine during X-ray photography of the female breast. U.S. Pat. No. 5,305,365 (the “'365 patent”), for example, discloses such a machine and is entitled “Mammography System With Rearwardly Tilting Mammograph”. The '365 patent is directed to a mammography system that includes a variable angle, rearwardly tilting mammograph. The '365 patent discloses a mammograph that consists of an x-ray tube mounted at an upper end of a system arm, and a film receptor mounted opposite the x-ray tube at a lower end of the system arm. The '365 patent discloses that the mammograph is tiltably-rotate—mounted on a support structure. The '365 patent states that the tilting direction is rearward from the vertical, and that the tilting axis is horizontal, in front of the patient, and extending laterally from one side to the other of the patient. The system arm of the mammograph can also be rotated in addition to being tilted.
U.S. Pat. No. 3,824,397 is entitled “Device for X-Ray Photography, In Particular for Mammography” shows a device including a support which is connected to a telescopic horizontal arm, is rotatable about the axis of the arm, and is also tiltable about an axis which is perpendicular to the arm. U.S. Pat. No. Des. 315,207 is entitled “Mammography Unit” and shows a mammography unit which appears to be vertically movable on a support column.
What is still desired, however, is a new and improved system and method for positioning a mammography unit. Preferably, the new and improved system and method will allow the mammography unit to be vertically raised and lowered, rotated, and tilted. In addition, the new and improved system and method will preferably allow an X-ray tube and a film receptor of the mammography unit to be independently rotated.